Legumes are a good source of bioactive compounds, including peptides with antidiabetic potential. The α-glucosidase inhibitory activity of simulated gastrointestinal digested (GID) soybean, chickpea, ...green pea, and navy bean was determined after using three different household cooking methods (conventional, pressure, and microwave cooking). Samples were analysed by reversed-phase high-performance liquid chromatography (RP-HPLC), and the fractions responsible for the α-glucosidase inhibitory activity were isolated. Lastly, peptides were identified by mass spectrometry in tandem (MS/MS) and in silico analyses were done to hypothesise potentially bioactive sequences. The results indicated that all legume extracts exert α-glucosidase inhibitory activity after thermal treatment and GID. Peptide profiles obtained by RP-HPLC showed the highest generation of peptides after the intestinal digestion phase, with small changes between thermal treatments. Best α-glucosidase inhibitory activity was observed in fraction 2 of all gastrointestinal digested samples, with values between 40 % and 62 % inhibition. In soybean, green pea, and navy bean, conventional-cooked samples showed the highest activity, while the pressure-cooked treatment resulted in significantly higher activity in chickpea samples. Finally, 48 peptides were identified by MS/MS and 13 were found as potentially bioactive using in silico tools, expanding previous knowledge on antidiabetic peptides derived from legumes.
•Legumes exert α-glucosidase inhibitory activity after cooking and digestion.•Thermal treatment did not affect the peptide profile of intestinal-digested legumes.•The activity of legumes was concentrated in a polar fraction from RP-HPLC.•13 of 48 peptides identified by MS/MS were predicted in silico as bioactives.
The tartary buckwheat protein isolates (TBPIs) were extracted by different pH combined with isoelectric precipitation. The impacts of extraction pH on Osborne-type protein fractions, functional ...properties, structural properties, and in vitro gastrointestinal digestion were investigated. The result showed that alkaline extraction was effective to increase yield of TBPI. With increase of extraction pH, the content of albumin in TBPI gradually decreased, while content of glutenin was increased. The solubility of TBPIs extracted by pH above 12 were significantly decreased while emulsion stability was significantly increased, which was related to significant increase of surface hydrophobicity. The digestive rate of TBPIs of pH 7 and 8 were high. With increase of pH from 8 to 10, digestive rate of TBPIs decreased. It was related to the compact structure of TBPIs, which had higher α-helix content, higher disulfide bonds, and lower intrinsic fluorescence intensity. Continuous increase of pH increased digestive rate of TBPIs. It was associated with unfolded and denatured structure of TBPIs (pH ≥ 12), as evidenced by breakdown of disulfide bonds, lower α-helix structure, red-shift in intrinsic fluorescence, and dissociation of subunits. Overall, extraction pH during protein extraction has great impacts on TPBIs.
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•Alkaline condition improved yield of tartary buckwheat protein isolates (TBPIs).•Different extraction pH changed Osborne-type fractions in TBPIs.•Functional or structural properties of TBPIs greatly changed at pH higher than 12.•The lowest in vitro digestion rate was found in TBPI obtained at pH 10.•The differences in in vitro digestion rate of TBPIs were related to structure.
•Microencapsulation in complex coacervated double emulsions and drying was proposed.•Hydrophilic emulsifiers influenced MEE and controlled release of the microcapsules.•In vitro release of SDE and ...FDE fit first order and Higuchi models, respectively.•Release mechanism of the microcapsules was controlled by erosion.
This study aimed to prepare anthocyanin-rich microcapsules by spray and freeze-drying complex coacervated double emulsion using gelatin-acacia gum (GE-AG) and chitosan-carboxymethylcellulose (CS-CMC) and to investigate their properties and in vitro release kinetics. Microencapsulation efficiency (MEE) of the microcapsules varied from 84.9% to 94.7%. CS-CMS microcapsules showed significantly higher MEEs than those of GE-AG microcapsules. A significant higher MEE and lower moisture content and hygroscopicity was observed in spray-dried double emulsion (SDE) microcapsules. Freeze-dried double emulsion (FDE) microcapsules possessed higher total anthocyanin and total phenolic contents. The best fit for release kinetics was achieved using first-order and Higuchi models for SDE and FDE microcapsules, respectively. Diffusion-controlled release in the simulated gastric fluid was found for SDE microcapsules, while erosion-controlled release in simulated gastric and intestinal fluids predominated for FDE microcapsules. These findings suggest that the microcapsules can be applied for loading anthocyanins as a nutraceutical with controllable release requirement.
This study explored the feasibility of a novel solid-like fat stabilized by porcine plasma protein (PPP) and carrageenan (CG) coupling emulsifier as curcumin delivery vehicle. The combination of 2.0% ...(w/v) PPP and 0.3% (w/v) CG successfully stabilized the oil of 80% (v/v) volume fraction at solid-like state, and the increasing of oil phase led to the increase in droplet size, storage modulus (G′) and apparent viscosity. Compared with free oil, oxidation of PPP-CG-stabilized solid-like fat could be significantly inhibited. The results from in vitro simulated digestion showed that the release rate of free fatty acids and bioaccessibility of curcumin in the solid-like fat were significantly higher than those in free oil, and curcumin was almost not released in simulated gastric fluid, but mainly released in simulated intestinal fluid. Therefore, PPP-CG-stabilized solid-like fat could be used as an effective nutrient delivery vehicle for food and pharmaceuticals, and the work provided some new insights into the structure design of functional food.
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•Porcine plasma protein - carrageenan could solidify oil volume fraction of 80%.•Oxidation of the solid-like fat could be significantly retarded.•Release rate of fatty acids in the solid-like fat increased significantly.•Bioavailability of curcumin in the solid-like fat increased significantly.•The solid-like fat could be an effective delivery vehicle for nutrients.
Phenolics in bound form extensively exist in cereal dietary fiber, especially insoluble fiber, while their release profile in gastrointestinal tract and contribution to the potential positive effects ...of dietary fiber in modulating gut microbiota still needs to be disclosed. In this work, the composition of bound phenolics (BPs) in triticale insoluble dietary fiber (TIDF) was studied, and in vitro gastrointestinal digestion as well as colonic fermentation were performed to investigate BPs liberation and their role in regulating intestinal flora of TIDF. It turned out that most BPs were unaccessible in digestion but partly released continuously during fermentation. 16 s rRNA sequencing demonstrated that TIDF possessed prebiotic effects by promoting anti-inflammatory while inhibiting proinflammatory bacteria alongside boosting SCFAs production and antioxidative BPs contributed a lot to these effects. Results indicated that TIDF held capabilities to regulate intestinal flora and BPs were important functional components to the health benefits of cereal dietary fiber.
•19 bound phenolics (BPs) were found in triticale insoluble dietary fiber (TIDF).•The release profile of BPs in gastrointestinal tract was uncovered in vitro.•The liberated BPs showed noticeable radical scavenging abilities.•BPs in TIDF showed synergetic prebiotic effects with fiber component.
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•Heat-induced protein digestibility was related to moisture content in whole soybeans.•Loose protein structure and increased digestibility was observed in 7S-denatured soybeans for ...each moisture content.•Protein digestibility reduced at 10.68% and 29.70% moisture content, but rose at 46.29% and 62.05% when 11S denatured.•Protein oxidation and β-sheet content were negatively correlated with in vitro digestibility.•A positive correlation was found between non-covalent interactions and in vitro digestibility.
The effects of heat treatment on protein structure and in vitro digestibility in whole soybeans with different moisture content (10.68%, 29.70%, 46.29%, and 62.05% wet basis) were investigated. Scanning electronic microscopy presented that thermal treatment destroyed the subcellular structure of soybean seeds and resulted in formation of protein aggregates. When β-conglycinin (7S) was heat-denatured, the protein aggregates were maintained mainly by hydrogen bonds and hydrophobic interactions (non-covalent) for each moisture content. Also, the decrease of the protein solubility and increase of in vitro digestibility were observed. However, when glycinin (11S) was denatured in soybeans with 10.68% and 29.70% moisture content, the insoluble and indigestible protein aggregates with protein oxidation-induced crosslinking and high content of β-sheet were presented; in contrast, for 46.29% and 62.05% moisture content, mild protein oxidation, low content of β-sheet, non-covalent interactions and increased protein digestibility were shown. Non-covalent interactions were shown a positive correlation with gastrointestinal digestibility (r = 0.59, p < 0.05). Meanwhile, protein oxidation or β-sheet content was significantly negatively correlated with in vitro protein digestibility (r = -0.69 and −0.61, respectively, p < 0.05). Protein structure rather than solubility contributed to difference of in vitro digestibility. The optimum thermal conditions to obtain high-quality digestible protein in whole soybeans are 160 °C for 10.68%, 145 °C for 29.70%, 160 °C for 46.29% and 115 °C/140 °C for 62.05% moisture content.
This study aimed to enhance the resistance of bread to gastrointestinal digestion by partially substituting wheat flour with starch spherulites. Three types of starch spherulites, specifically A-type ...(exhibiting an A-type crystalline pattern with mostly positive birefringence), B(−)-type (B-type crystalline with negative birefringence), and B(+)-type (B-type crystalline with positive birefringence), were investigated. The A-, B(−)-, and B(+)-type spherulites showed significantly higher resistant starch contents of 63.5, 63.8, and 89.2 %, respectively, compared to the control wheat flour (7.4 %). The melting temperatures of A-type and B(+)-type spherulites were notably higher than those of the control wheat flour, suggesting the potential preservation of certain enzyme-resistant starch during the baking process. The partial substitution of wheat flour with spherulites resulted in a denser crumb structure, increased bread hardness and chewiness, and a pale brown color in the case of B(+)-type spherulite. However, these variations in physicochemical properties did not significantly impact consumer acceptability. Remarkably, in bread containing A- or B(+)-type spherulite, residual ordered spherulite structures were present after baking, as confirmed by differential scanning calorimetry. This resulted in significantly lower digestibility during in vitro gastrointestinal digestion. These findings are useful for the rational design of bread with sustained glucose release during gastrointestinal digestion.
•Starch spherulites with different allomorphs and birefringent signs were prepared.•Starch spherulites exhibited heat- and enzyme-resistance compared to wheat flour.•Spherulites with positive birefringence maintained enzyme-resistance during the baking process.•Substituting wheat flour with spherulites with positive birefringence impeded bread digestion.•Consumer acceptability was similar for both control and spherulite-containing bread.
To improve the viability of Lactobacillus plantarum (P) during digestion and storage, the probiotics were encapsulated by alginate (ALG) and alginate-gelatin (ALG-GE) hydrogels beads. ALG-P-GE showed ...much better physicochemical properties than ALG-P. The scanning electron microscopy (SEM) results validated the incorporation of bacterial cells into the beads. ALG-P-GE exhibited good encapsulation efficiency of 97.7 %, and the storage and thermal stability of probiotic were increased by 15 % and 8 %, respectively, when comparing with ALG-P. ALG-P-GE beads could protect the probiotics from inactivation in simulated gastric fluid and then release it in simulated intestinal fluid. The protective mechanism of ALG-GE for probiotics was further studied by fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD) and found that ALG and GE can form gel network through hydrogen bonding and electrostatic interactions. In the mimic beverage systems, ALG-P-GE beads could protect the encapsulated probiotics and increase its viability. The storage, thermal, and digestion stability of encapsulated probiotic were significantly increased and showed high viability in the mimic beverage systems. ALG-P-GE beads have great potential for the protection and delivery of probiotics in food systems.
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•ALG-GE hydrogel beads exhibit high encapsulation efficiency of 97 % for probiotics.•ALG-P-GE hydrogel beads have better storage and thermal stability.•ALG-GE achieves the rapid release of probiotics in simulated intestinal digestion.•ALG-GE protects the probiotics in low acidic solutions and different mimic milk tea systems.
The release and hydrolysis of maltose from six classic polysaccharide-based hydrogels (agar, low acyl gellan, κ- and ι-carrageenan, sodium alginate and konjac glucomannan) containing 1% gelling agent ...and 10% maltose were compared under sequential in vivo oral, simulated gastric (SGD) and intestinal digestions (SID). The incorporation of maltose into hydrogels obstructed up to 35% maltose digestion and reduced the early stage of maltose hydrolysis by 40%–60%. The degree and the nature of obstruction were dependent on the polysaccharide structure and gel texture. Limited fragmentation of elastic and cohesive hydrogels and reduced maltose release in highly adhesive hydrogels both resulted in lower maltose release at the oral phase. The remaining large gel particles and dramatic gel microstructural changes as response to the gastric pH limited maltose release at SGD. Cumulative maltose release from oral processing and SGD contributed to initial maltose hydrolysis rate (HR) and the overall maltose hydrolysis in SID. Additionally, other factors were also involved. Release of polysaccharide from hydrogels under SGD stress and the formation of fine gel particles may have resulted in highly viscous or viscoelastic intestinal fluid and therefore decreased the speed of enzyme reaction. We believe that the information provided by the current study would help future design of hydrogel texture targeted at different incipient food component release and digestion profiles.
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•Serum release during gel fragmentation was the main source of maltose release at oral phase.•Lower serum release was correlated to high fracture strain, cohesiveness and adhesiveness of a hydrogel.•Maltose release during simulated gastric digestion depended on particle size reducing and microstructural shrinkage.•Amount of maltose in the digesta was correlated to the maltose hydrolysis during simulated intestinal digestion.
Umami peptides can help reduce the salt content in foods while still maintaining a savory taste. Few studies have reported the bioactivity of umami peptides after consumption. We studied the ...bioactivities of 12 umami peptides after gastrointestinal digestion. Three umami peptides exhibited angiotensin I-converting enzyme (ACE) inhibitory and antioxidant activity after digestion. Six novel peptides were identified from digestion solutions of the peptides by HPLC-MS/MS. Among them, CC, CCNK, and HCHT had both ACE inhibitory activity (IC
values were 9.81, 9.00, and 114.99 μM, respectively) and antioxidant activity (strong 1,1-Diphenyl-2-pycryl-hydrazyl (DPPH) and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS) free radical scavenging activities). AHSVRF had strong ACE inhibitory activity. These peptides increased the nitric oxide concentration and decreased the content of endothelin-1 in a medium of human umbilical vein endothelial cells in a dose-dependent manner. Experiments with damaged HepG2 cells showed that peptides CC, CCNK, and HCHT had antioxidant activity through their cytoprotective effects and by reducing the reactive oxygen species content. The results indicated that umami peptides may provide many health benefits after consumption.
